Digital video capabilities can be incorporated into a wide range of devices, including digital televisions, including so-called smart televisions, laptop or desktop computers, tablet computers, digital recording devices, digital media players, video gaming devices, cellular telephones, including so-called “smart” phones, medical imaging devices, and the like. Digital video may be coded according to a video coding standard. Examples of video coding standards include ISO/IEC MPEG-4 Visual and ITU-T H.264 (also known as ISO/IEC MPEG-4 AVC) and High-Efficiency Video Coding (HEVC), ITU-T H.265 and ISO/IEC 23008-2 MPEG-H. Extensions and improvements for HEVC are currently being developed. For example, the Video Coding Experts Group (VCEG) designates certain topics as Key Technical Areas (KTA) for further investigation. Techniques developed in response to KTA investigations may be included in future video coding standards, (e.g., “H.266”). Video coding standards may incorporate video compression techniques.
Video compression techniques enable data requirements for storing and transmitting video data to be reduced. Video compression techniques may reduce data requirements by exploiting the inherent redundancies in a video sequence. Video compression techniques may sub-divide a video sequence into successively smaller portions (i.e., groups of frames within a video sequence, a frame within a group of frames, slices within a frame, coding tree units (or macroblocks) within a slice, coding blocks within a coding tree unit, coding units within a coding block, etc.). Spatial techniques (i.e., intra-frame coding) and/or temporal techniques (i.e., inter-frame coding) may be used to generate a difference value between a coding unit to be coded and a reference coding unit. The difference value may be referred to as residual data. Residual data may be coded as quantized transform coefficients. Syntax elements (e.g., reference picture indices, motion vectors, and block vectors) may relate residual data and a reference coding unit. Residual data and syntax elements may be entropy coded.
Video coding standards may support temporal scalability. That is, video coding standards may enable a bitstream of encoded video data to be decoded at different frame (or picture) rates (e.g., 60 Hz or 120 Hz). For example, HEVC describes a sub-bitstream extraction process where encoded video frames within a sequence of encoded video data include respective temporal identifiers such that a particular subset of encoded video frames can be extracted for decoding. The extracted frames may be decoded and used to provide output video with a lower frame rate than the frame rate of the original sequence of encoded video data. However, the output video with a lower frame rate may include motion based artifacts.